Bluetooth: Fix LE SMP channel source address and source address type

The source address and source address type of the LE SMP channel can
either be the public address of the controller or the static random
address configured by the host.

Right now the public address is used for the LE SMP channel and
obviously that is not correct if the controller operates with the
configured static random address.

Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>